[Intel-gfx] [PATCH 099/190] drm/i915: Check for request completion before choosing CS flips

[Chris Wilson]

Only queue a CS flip if the outstanding request is not complete, and in
particular do not rely on the request tracking being fresh (since it is
only updated when requests are retired).

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_display.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index eef858d5376f..f227cdaf38ec 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11309,8 +11309,11 @@ static bool use_mmio_flip(struct intel_engine_cs *ring,
 		 !reservation_object_test_signaled_rcu(obj->base.dma_buf->resv,
 						       false))
 		return true;
+	else if (!obj->last_write.request ||
+		 i915_gem_request_completed(obj->last_write.request))
+		return true;
 	else
-		return ring != i915_gem_request_get_engine(obj->last_write.request);
+		return ring != obj->last_write.request->engine;
 }
 
 static void skl_do_mmio_flip(struct intel_crtc *intel_crtc,
-- 
2.7.0.rc3